The present invention relates to an indwelling balloon catheter for an endoscope.
When the indwelling balloon catheter is used, a flexible tube, which is a catheter, is guided to an objective region in the body cavity, through a treatment tool channel of the endoscope. Then, only the endoscope is pulled out from the body cavity, thereby leaving the flexible tube thereat.
For this purpose, a connector, which cannot pass through the treatment tool channel of the endoscope, is detachably provided at the proximal end of the flexible tube, and after the endoscope is pulled out from the body cavity, the connector is connected to the proximal end of the flexible tube. An example of such a configuration is disclosed, for example, in Japanese Patent Provisional Publication No. HEI 09-99059.
If such an indwelling catheter is used for radiation therapy with a small radiation source, in which a small chip of radiation source is introduced inside the tip end of the catheter, and radiation therapy is performed from the inside of the body, a balloon catheter provided with an expansible/contractible balloon at the tip end is used. With such a configuration, the distal end of the indwelling catheter can be secured stably inside the body cavity. Examples of such a configuration is disclosed in Japanese Patent Publication No. HEI 3-74589 and Japanese Utility Model Provisional Publication HEI 02-25256.
The balloon catheter as described above requires a main lumen for a passage that is used for introducing a radiation source to the tip end, and a sub lumen for ventilation that is used to feed air to expand/contradict the balloon. The sub lumen may have a smaller cross-sectional area than the main lumen.
Since such a sub lumen for ventilation has a relatively small diameter of about 0.3-0.5 mm, there is a difficulty in inserting a sub lumen connecting pipe and a main lumen connecting pipe into the sub lumen and the main lumen, respectively, simultaneously, in an endoscopic treatment room generally having a relatively dark environment. It has occurred that a series of procedures was often interrupted in order to connect the proximal end of the catheter to the connector. Thus, the conventional balloon catheter may impose a burden to operators and a patient.